Cable transportation system and relative drive method

ABSTRACT

A cable transportation system has rails and a draw cable, both extending along a transportation path, a drive member for driving the draw cable; at least one vehicle, which moves along the transportation path and has wheels which roll along the rails, and a coupling device for connecting the vehicle to the draw cable, at least one passenger station where the vehicle is stopped and an electric machine located on the vehicle and driven by the wheels to generate electric power.

PRIORITY CLAIM

This application is a national stage application of PCT/EP2008/054774,filed Apr. 18, 2008, which claims the benefit of and priority to ItalianPatent Application No. MI2007A 000835, filed on Apr. 20, 2007, theentire contents of which are incorporated herein.

TECHNICAL FIELD

The present disclosure relates to a cable transportation system. Morespecifically, the present disclosure relates to a cable transportationsystem comprising rails and a draw cable, both extending along atransportation path; a drive member for driving the draw cable; and atleast one stop station, located along the transportation path, for avehicle which moves along the transportation path and comprises wheelswhich roll along the rails, and a coupling device for connecting thevehicle to the draw cable.

BACKGROUND

Cable transportation systems are described in Patents EP 0 687 607 B1and EP 1 088 729 B1, and have proved particularly suitable for passengertransport, and cheaper than other passenger transport systems in givenurban applications and for given passenger transport requirements.

In certain known cable transportation systems, each vehicle is drawn bythe draw cable along the transportation path on the rails, and, at thepassenger station, is released from the draw cable and moved along bydeceleration conveyors and acceleration conveyors, which engage bothsides of the vehicle at the passenger station.

In these known systems, the deceleration conveyors operate when thevehicle is released from the draw cable, to brake and stop the vehiclein a stop position allowing passengers to board and alight; and theacceleration conveyors operate downstream from the stop position at thestation, to accelerate the vehicle from the stop position to a speedsubstantially equal to the speed of the draw cable, so the couplingdevice can reconnect the vehicle smoothly to the draw cable.

In these known systems, each vehicle can only be powered electrically atthe passenger station, during the relatively short time it remains inthe stop position, which therefore greatly restricts electric powersupply on the vehicle itself, and the possibility of equipping thevehicle with electrically powered user devices for enhanced passengercomfort.

The same lack of power supply also exists in other types of cablesystems, in which the vehicle is connected permanently to the cable, andis stopped at the passenger stations by stopping the draw cable. Thistype of cable system is normally referred to as a “to-and-fro” system,and the passenger stations are normally, though not necessarily, locatedat the ends of the path.

SUMMARY

It is an advantage of the present disclosure to provide a cabletransportation system of the above type, designed to eliminate thedrawbacks in the known art.

According to various embodiments of the present disclosure, there isprovided a cable transportation system comprising rails and a drawcable, both extending along a transportation path; a drive member fordriving the draw cable; at least one vehicle, which moves along thetransportation path and comprises wheels which roll along the rails, anda coupling device for connecting the vehicle to the draw cable; and atleast one passenger station where the vehicle is stopped; the vehiclecomprising an electric machine driven by the wheels to generate electricpower on board the vehicle and the coupling device being selectivelydisconnectable at the passenger stations; wherein the vehicle comprisesa control unit and a selector, the control unit being suitable to setthe selector to a dissipating operating mode to regulate the amount ofpower dissipated and so regulate the braking force of the electricmachine.

The present disclosure also relates to a method of driving a cabletransportation system.

According to various embodiments of the present disclosure, there isprovided a method of driving a cable transportation system comprisesadvancing a vehicle fitted with wheels resting on rails extending alonga transportation path; driving the vehicle by a draw cable extendingalong the transportation path and driven by a drive member; stopping thevehicle at at least one passenger station located along thetransportation path; and driving an electric machine by the wheels ofthe vehicle, to generate electric power on board the vehicle; regulatingelectric power flow to and from the electric machine by a selector onboard the vehicle; and regulating by said selector dissipation of theelectric power generated by the electric machine, so as to regulate thebraking force of the electric machine.

Additional features and advantages are described in, and will beapparent from, the following Detailed Description and the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

A number of non-limiting embodiments of the present disclosure will bedescribed by way of example with reference to the accompanying drawings,in which:

FIG. 1 shows a view in perspective, with parts removed for clarity, of acable transportation system in accordance with a first embodiment of thepresent disclosure;

FIG. 2 shows a larger-scale front elevation, with parts in section andparts removed for clarity, of the FIG. 1 cable system;

FIG. 3 shows a larger-scale section, with parts removed for clarity, ofa detail of a vehicle forming part of the FIG. 1 system;

FIG. 4 shows a plan view, with parts removed for clarity, of a cabletransportation system in accordance with a second embodiment of thepresent disclosure.

DETAILED DESCRIPTION

Referring now to the example embodiment of the present disclosureillustrated in FIGS. 1 to 4, number 1 in FIG. 1 indicates a cabletransportation system for passenger transport. Cable transportationsystem 1 comprises a fixed structure 2 (FIG. 2) for supporting a pair ofparallel rails 3 defining an endless transportation path P; a continuousdraw cable 4 extending along transportation path P; a drive station 5for driving draw cable 4; a number of vehicles 6 (only one shown inFIG. 1) movable along transportation path P and connectable selectivelyto draw cable 4; and a number of passenger stations 7 (only one shown inFIG. 1) where each vehicle 6 is stopped cyclically to allow passengersto board and alight from vehicle 6.

Passenger station 7 comprises a deceleration portion 7 a, of length D,where vehicle 6 is decelerated; a stop position 7 b, where vehicle 6 isstopped; and an acceleration portion 7 c, of length A, where vehicle 6is accelerated.

With reference to FIG. 2, fixed structure 2 is anchored to a base 8, andprovides for supporting rails 3, guiding draw cable 4 by guide rollers 9and 10, and supporting a pair of runners 11 extending at passengerstation 7, and which cooperate with vehicle 6 to connect and releasevehicle 6 to and from draw cable 4. Each rail 3 has a top supportingface 12 and an inner lateral supporting face 13.

With reference to FIG. 1, the two runners 11 extend along path P,between the two rails 3, at deceleration portion 7 a and accelerationportion 7 c, as described in Patent EP 0687 607 B1.

The stop position 7 b separating deceleration portion 7 a andacceleration portion 7 c is defined with a narrow tolerance of about 20cm (or 7.87 inches).

Drive station 5 comprises a winch 14 of axis A1; and an electric motor15 for rotating winch 14 about axis A1 continuously at constant speed,and moving draw cable 4 at constant speed along path P.

With reference to FIG. 2, vehicle 6 comprises a frame 16; a number ofsupporting wheels 17; a number of direction wheels 18; a cab 19 on topof frame 16; and a coupling device 20 for connection to draw cable 4.Coupling device 20 is of the type described in Patent EP 0687 607 B1,and cooperates with the two runners 11 at each passenger station 7 asdescribed in Patent EP 0687 607 B1.

For each supporting wheel 17, vehicle 6 comprises an electric machine21, which acts as a generator, motor, and brake. Vehicle 6 comprises aselector 22 for modulating electric power flow; an electric poweraccumulator 23; an electric user device 24; and a control unit 25, inturn comprising a computing module 25B and a regulating module 25C.

Each wheel 17 is directional, rotates about a horizontal axis A2, andcomprises a tire 26 resting on the top supporting face 12 of a rail 3;and each direction wheel 18 rotates about a vertical axis A3, is forcedagainst the inner lateral supporting face 13 of a rail 3 by elasticmembers (not shown), and is fitted to a movable arm 27 connected to arespective wheel 17, and which imparts a steering moment to wheel 17,depending on the position of direction wheel 18. This method oforienting wheels 17 is made possible by axis A3 of direction wheel 18and axis A2 of respective wheel 17 lying in different planes.

With reference to FIG. 3, each wheel 17 comprises a hub 28 supporting awheel rim 29, in turn supporting tire 26, and is mounted to rotate abouta pin 30 connected to arm 27 and hinged to frame 16 about a steeringaxis A4. A rolling bearing 31 is interposed between pin 30 and hub 28.Hub 28 comprises an annular portion 32 projecting on the opposite sideto frame 16, and in which is formed a seat for the rotor 33 of electricmachine 21. Each wheel 17 has a cover 35 formed by two connected flanges36 and 37, which enclose an annular stator 38 of electric machine 21.Cover 35 is fixed to pin 30, and provides for supporting stator 38 andprotecting electric machine 21 from the surrounding environment. Stator38 comprises a core 39 of ferromagnetic material, and an electricwinding 40 supported by core 39.

In an embodiment not shown in the drawings, the rotor extends about thestator.

With reference to FIG. 2, vehicle 6 comprises a brake 41 at each wheel17; and a speed sensor 42, which transmits a speed signal SV, related tothe instantaneous speed of vehicle 6, to control unit 25.

Cable transportation system 1 according to the present disclosuregenerates electric power when vehicle 6 is moving, and uses thegenerated electric power to power user device 24, which indicates as awhole one or more user devices, such as an interior lighting system ofvehicle 6, and exterior lighting system of vehicle 6, a heating systemof vehicle 6, an air-conditioning system of vehicle 6, etc. User device24 also represents as a whole a group of different user devices ingeneral, and supplies an absorption signal SA to computing module 25B.

Operation wise, electric machines 21 at respective wheels 17 generateelectric power which is stored in accumulator 23 by selector 22; andaccumulator 23 powers user device 24, as required, by selector 22 andunder the control of control unit 25 which coordinates operation ofselector 22.

Electric machines 21 operate as generators along the whole oftransportation path P, with the exception of the portions at passengerstation 7, where control unit 25 operates electric machines 21 asgenerators, motors, and brakes, depending on circumstances.

Electric machines 21 on board vehicle 6, and brakes 41 eliminate theneed to install, at each passenger station 7, the deceleration andacceleration conveyors described in Patent EP 0 687 607 B1.

Without deceleration conveyors, vehicle 6 is decelerated as follows:once the draw cable is detached from vehicle 6, vehicle 6 is braked byelectric machines 21, which absorb power by operating as electric powergenerators, and by the normal rolling friction of wheels 17 anddirection wheels 18 on rails 3. These braking forces, however, do notguarantee stoppage of vehicle 6 at stop position 7 b and at the requiredspeed. Moreover, the mass of vehicle 6 varies, depending on the numberof passengers; and other uncontrollable parameters, such as externaltemperature and humidity, may also affect the forces in play whendecelerating vehicle 6. For this reason, computing module 25B receivesspeed signal SV from sensor 42, and compares speed signal SV with adeceleration speed curve SVD corresponding to the ideal decelerationspeed, as a function of time, from the start of deceleration portion 7 ato stop position 7 b. Whenever speed signal SV exceeds the ideal speed,according to deceleration speed curve SVD, by more than a givenacceptance range, control unit 25 transmits an instantaneous actuatingsignal F1 to brakes 41.

When speed signal SV falls below the ideal speed by more than therelative acceptance range, regulating module 25C, under the control ofcomputing module 25B, emits an actuating signal F2 to instantaneouslyoperate at least one electric machine 21 as a motor.

The instantaneous speed SV of vehicle 6 is compared repeatedly withdeceleration speed curve SVD and acceleration speed curve SVA, and, bysuccessive adjustments, control unit 25 guides vehicle 6 into stopposition 7 b. Once the passengers have alighted or boarded, vehicle 6 isready to depart.

Alternatively, vehicle 6 is braked solely by electric machines 21operating as brakes. That is, when speed SV of vehicle 6 is greater thandeceleration speed SVD, regulating module 25C, in accordance withinstructions from computing module 25B, transmits a signal F2 toselector 22, which increases the electric absorption, and hence thebraking force, of electric machines 21. Regulating the braking force ofelectric machines 21 allows brakes 41 to be omitted. Alternatively,electric machines 21 brake vehicle 6 together with brakes 41.

Operated as brakes, electric machines 21 may be used to advantage asemergency brakes: computing unit 25B is supplied by the control system(not shown) of cable transportation system 1 with a signal SRC relatingto the integrity of draw cable 4. When signal SRC assumes a valueindicating failure of draw cable 4, the computing module transmits asignal to regulating module 25C, which, by means of signal F2, setsselector 22 to maximum absorption (resistance) to enable electricmachines 21 as brakes—in this case, as emergency brakes. In other words,selector 22 can be operated as a power dissipater.

The start signal to start vehicle 6 is received by control unit 25 fromthe control system (not shown) of cable transportation system 1; and, onreceiving the start signal, control unit 25 commands selector 22 topower all the electric machines 21 as motors. In this case too,computing module 25B compares vehicle speed SV with an idealacceleration speed curve SVA, calculated as a function of the speed SCof the cable, and accelerates or decelerates vehicle 6 by adjustingpower supply to electric machines 21, depending on the deviation ofspeed signal SV with respect to acceleration speed curve SVA and therelative acceptance range. Vehicle 6 is thus brought to substantiallythe same speed as speed SC of draw cable 4 by the end of portion 7 c,and can therefore be connected smoothly to draw cable 4.

In other words, the power supplied on board vehicle 6 is substantiallythat transmitted to draw cable 4 in the form of kinetic energy at drivestation 5 and temporarily stored in accumulator 23 for use inaccelerating vehicle 6. This power is supplied to user device 24, fedback to wheels 17 as drive power, and, if necessary, dissipated whenoperating electric machine 21 as a brake.

In the FIG. 4 embodiment, number 43 indicates a passenger “to-and-fro”cable transportation system, which comprises two parallel rails 44defining a straight transportation path P1; a continuous draw cable 45extending along transportation path P1; a drive station 46 for drivingdraw cable 45; a vehicle 47 movable along transportation path P1 andconnected to draw cable 45; and two passenger stations 48 located atopposite ends of transportation path P1, and where vehicle 47 is stoppedto allow passengers to board and alight from vehicle 47.

Drive station 46 comprises a winch 49 about axis A5; and an electricmotor 50 for rotating winch 49 about axis A5, and moving draw cable 45along path P1. Vehicle 47 is reversed and stopped at passenger stations48 by winch 49.

Vehicle 47 is equipped with an electric machine 21 of the type describedwith reference to the first embodiment of the present disclosure, andwhich acts as a current generator, and, in the event of failure of drawcable 45, as an emergency brake and as a motor to return vehicle 47 topassenger station 48. The component parts are substantially the same asin the first embodiment, and operation differs solely as regardsselective connection to the draw cable.

In transportation system 43, brake and motor operation of electricmachine 21 assists operation of draw cable 45.

It should be understood that various changes and modifications to thepresently preferred embodiments described herein will be apparent tothose skilled in the art. Such changes and modifications can be madewithout departing from the spirit and scope of the present subjectmatter and without diminishing its intended advantages. It is thereforeintended that such changes and modifications be covered by the appendedclaims.

The invention claimed is:
 1. A cable transportation system comprising: aplurality of rails extending along a transportation path; a draw cableextending along the transportation path; a drive member configured todrive the draw cable; at least one passenger station; and at least onepassenger vehicle configured to move along the transportation path andstop at the at least one passenger station, said at least one passengervehicle including: a plurality of wheels configured to roll along therails, each wheel including a hub configured to rotate about a pin, acoupling device configured to connect the passenger vehicle to the drawcable, and to be selectively disconnected from the draw cable at the atleast one passenger station, at least one electric machine fitted to oneof the wheels, said at least one electric machine being driveable by thewheel to generate, independent of any braking of the passenger vehicle,electric power on board the passenger vehicle, said at least oneelectric machine including a stator and a rotor fitted to the hub, atleast one user device powered by the electric power generated by the atleast one electric machine, a selector coupled to an accumulator, saidselector configured to regulate flow of the generated electric powerbetween the at least one electric machine, the accumulator and the atleast one user device, and a control unit configured to set the selectorto a dissipating operating mode to regulate the amount of powerdissipated and to regulate the braking force of the electric machine. 2.The cable transportation system of claim 1, wherein the accumulator isconfigured to store the power generated by the at least one electricmachine.
 3. The cable transportation system of claim 1, wherein for eachpassenger vehicle, the at least one electric machine is reversible, andconfigured to supply drive torque to at least one of the wheels.
 4. Thecable transportation system of claim 1, wherein each passenger vehicleincludes a plurality of electric machines, each of said electricmachines being fitted to the hub of a corresponding one of the wheels ofsaid passenger vehicle.
 5. A passenger vehicle configured to move alonga transportation path, the vehicle including: at least one wheelconfigured to roll along the transportation path, said wheel including ahub configured to rotate about a pin; a coupling device configured toconnect the passenger vehicle to a draw cable, said coupling deviceconfigured to be selectively disconnected from the draw cable at apassenger station; an electric machine fitted to the wheel and driven bythe at least one wheel to generate, independent of any braking of thepassenger vehicle, electric power on board the passenger vehicle, saidelectric machine including a stator and a rotor fitted to the hub; andat least one user device powered by the electric power generated by theelectric machine.
 6. The passenger vehicle of claim 5, which includes anaccumulator configured to store the electric power generated by theelectric machine.
 7. The passenger vehicle of claim 5, wherein theelectric machine is reversible, and configured to supply drive torque tosaid at least one wheel.
 8. The passenger vehicle of claim 5, wherein aselector is associated with an accumulator, said selector configured toregulate flow of the generated electric power between the electricmachine, the accumulator, and the at least one user device.